Caution

A treatment billed as a potential breakthrough in the fight against disease, including cancer, could back-fire and make the disease fitter and more damaging, new research has found.

Ground-breaking research has found that introducing ‘friendlier’ less-potent strains into a population of disease-causing microbes can lead to increased disease severity.

The surprise findings by a team of scientists at the University of Exeter has led to calls for urgent research into the implications of using ‘fire to fight fire’ to combat disease. The research shows that far from being a ‘silver bullet’ to weaken disease, the practice of introducing pacifist microbes into a host could make the aggressive pathogen stronger, which could hamper disease management.

Until now, introducing friendlier cousins, which do not cause severe disease, into a population of pathogens has been shown to reduce disease severity and damage to the infected host. It has been suggested that this approach could be an effective way of treating cancer, and research so far has proved effective and promising. For example, scientists have already produced encouraging results in the fight against Clostridium difficile infections that are so common in our hospitals.

But the University of Exeter scientists tested this strategy using a plant pathogen, and found the therapy could go dramatically wrong, with devastating consequences for the host plant.